Head lice infestation is a persistent problem with as many as 6-12 million people worldwide affected each year. The problem is particularly prevalent in children with preschool and elementary-age children aged 3-10 and their families becoming infested most often. Head lice infestation is produced by the common head louse Pediculus humanus capitis, and typically causes itching of the scalp. As the lice feed on human blood, they may cause lesions to develop on the scalp, swollen glands on the neck or under arms, or other symptoms. Head lice infestation causes serious problems due to the negative social implications of the infestation. Body lice are also bothersome to humans and carry the additional hazard of being the vectors of certain diseases, such as exanthematic or epidemic typhus and recurrent fever.
Various compositions are available for treating these infestations, which generally take a topical approach to treatment. Most of these treatments involve the use of insecticides that are harsh agents, thus raising toxicity concerns. The lice can also become resistant to the insecticides used and therefore the compositions can lose their effectiveness over time.